Cellulose-ether composition



. No Drawing.

Patented Feb. 7,19%.

UNITED STATES PATENT OFFICE.

STEWART J. CARROLL, OF ROCHESTER, NEW YORK, ASSIGNOB TO EASTMAN KODAK COMPANY, 01 ROCHESTER, NEW YORK, A CORPORATION 01? NEW YORK.

- CELLULOSE-ETHEB COMPOSITION.

This invention relates to a composition of matter in which cellulose ether is combined or mixed with. other substances, so that the resulting product can be advantageously used in the plastic and analogous arts, such injured by the substances with which it is v associated during manufacture, storage or use. Still another object of my invention is to provide a film having the her'einabove' described properties. Other objects will hereinafter appear.

I have found that a composition having the desirable qualities hereinabove enumerated can be obtained by mixing or compounding cellulose ether, say for example an alkyl ether of the type described in U. S, Patent No. 1,188,376, .June 20, 1916, Leon Lilienfeld,with one or more of the acetins,--mono, di or tri or mixtures of them. It is an inherent property of the acetins that they are non-solvents of cellulose ether, 1) which I mean that the addition of enougi of them to a solution of said either will precipitate said ether from the solution. to a colloidized state is preferably performed with the aid of a common solvent. \Vhile the details of one way of carrying out my invention will be givenby way of example, it will be understood that my invention is not restricted thereto, except as indicated in the appended claim. y

In carrying outone embodiment of my invention, 100 parts of water-insoluble ethyl cellulose are dissolved along with from 5 to parts of either mono, di, or tri acetin "or a mixture of them (say 10 parts) in from 300 to 500 parts of a volatile common solvent. The latter may usefully comprise a mixture of methyl acetate and methyl alcohol, the weight of methyl acetate being approximatel y nine times the weight of the alcohol. This This mixing- .irom color.

Application filed October 7, 1925. Serial No. 01,148.

composition is suitable for spreading upon a film-forming surface in a coating, from the acetins' remain in the colloidized state without'precipitating each other. Where the minimum hygroscopicity is desired in the product, I can use purified tri- 'acetin, practically free from the other acetins. but moisture in small amounts helps to maintain the flexibility of the films; so I I prefer to add small amounts of mono and/or di acetin along with the tri acetin and thus control the hygroscopicityof the mixture,

iVhere a more readily fiowable composition is desired, the amount of volatile solvent may be increased until the desired results are obtained. Benzol and ethyl or methyl alcohol may be added in thinning it out. Of course, other equivalent volatile solvent mixtures maybe substituted. Moreover,'-ingredients which impart characteristicv properties to the film may likewise be added, such as triphenyl phosphate, tricresyl phosphate, camphor, monochlornaphthalene, etc. The proportions of these substances or mixtures of them, should not be sufficient to cause precipitation of the ether, or to cause white films or varnish coatings to beproduced. The ingredients are of the eon'imercialtype and sufficiently purified for the ends in view. Where the dope is'to be made into sheets or films for photographic purposes, the substances are chosen or purilied to have the proper relative freedom Having thus described my invention, what I claim as new and desire to secure by Letters Patent is: I

As an article of manufacture, a flexible, transparent, deposited or flowed sheet, comprising water-insoluble, alkyl cellulose and Signed at Rochester, New York this 30th day of September 1925.

I STEWART J. CARROLL. 

